The U.S. pop star will be on the South American leg of her "Femme Fatale" world tour as she celebrates the landmark birthday on Dec. 2.
"I hear the older you get, the wiser you get and the more you know what you want - so hopefully it'll be a good year," the woman who was once one of the Internet's most-searched names told The Associated Press.
Spears kicks off a string of European tour dates Thursday in St. Petersburg, but is not scheduled to play on the birthday itself. She has spent the summer performing across North America to generally positive reviews.
"The audiences have been just amazing, they've been so great to bounce off of and the energy I get from them, it's great, it's really cool," she said.
Her seventh studio album, "Femme Fatale," debuted at No. 1 in the U.S. Billboard charts and globally, and Spears targeted it at her female fans.
"With the big picture of being "Femme Fatale," I think it is really inspiring for girls all together feeling very empowered and having a voice and being heard," she said.
The singer was in London to promote her U.K. gigs, which include two in October at London's O2 Arena. After Russia, she tours across Europe - from Hungary and France to Sweden, Germany and Britain - before heading to South America in November.
With more than 35 gigs left to play before her final date - Dec. 10 in San Juan, Puerto Rico - it's a demanding schedule, and saying healthy and fit is high on her agenda.
"I have a good group of people around me, and we have the show at a certain time every night and we just try to stay consistent on having a routine and staying fit and healthy," she said.
A former child performer, Spears shot to international fame with her 1999 debut album, "Baby One More Time." The hits kept coming including "Oops!.. I Did It Again" and "Toxic," but her personal life spiraled out of control. She lost temporary custody of her two young boys, had spells in rehab and was admitted to a psychiatric ward.
Four years after that public meltdown, Spears is looking forward. And with more than 70 million albums already sold, she says the pressure is off.
"You know, I don't really have anything to prove at this point, so it's like I just do it for fun and just see what happens," she said.